Hi, ive put a disco 200tdi into my defender. Basically on start up the engine wont rev and bellows out white smoke. Its also a little underpowerd which is noticible mainly when pulling away in first untill the turbo kicks in. Also noticed its low on oil (dropped to the min level in 800 miles) also the coolant level is low. Also noticed that wher the bellhousing is there is a little oil leak (always has been) but now it appears that coolant is leaking out of there as well. Is this a head gasket or somthing else? Cheers for any advice! Pete
I'm supposed to be doing a uni essay but I can't keep off here! It doesn't sound good to me but all signs are pointing towards a blown head gasket or possibly (worse) a crack in your cylinder head or the block. The first thing that I'd be checking is that there are no coolant leaks anywhere externally, especially where the heater matrix pipes connect towards the back of the engine. Even water leaking past your jubilee clips towards the front of the engine will find its way down to the bell housing when travelling.
If you look at the dipstick, does it show any signs of water contaminating the oil or does the oil look very diluted? Usually you'd find that if water is getting into the oil, your oil level will increase but it would depend very much on which part of the head gasket has blown. This is what I find puzzling about your situation. For oil to find its way into the bell housing, it must be getting past the crank rear oil seal and for you to find coolant in there too, your oil level would almost certainly show signs of increasing volume or water dilution.
The best thing to do, as is always the case in these situations, is to have the engine 'leakage tested'. I'd strongly suggest that you do this before you decide to whip the head off (which it sounds like it needs either way) because at least then you will know which cylinder(s) are playing up and you'll know to check those particular cylinders particularly carefully for cracks etc.
A head gasket can blow in quite a few different ways and in most cases, you should be able to get a dead-cert answer with a few simple tests:
1) Start your engine and let it run up to temperature.
2) Remove the breather pipe between the cyclone breather and your air intake - but not the pipe between the cyclone unit and the sump.
3) Press your thumb firmly over the opening of the cyclone unit opening
4) Rev the engine hard for five seconds
5) Quickly release your thumb
Does it throw a smelly oily vapour / oil out at you and hiss? If so, you have a head gasket leak between a cylinder and an oil passage / push rod hole.
Repeat the steps above, but whilst keeping your thumb pressed over the cyclone unit hole, have someone remove the dipstick after five seconds of hard revving - does it hiss? This will also confirm headgasket failure between a cylinder and an oil passage / push rod hole.
6) Replace the breather pipe
7) Place a towel firmly over the top of the header tank cap
8) Remove the cap from your header tank carefully
Does it blow the cap off?
9) With the header tank cap removed, rev the engine
Do you see any bubbles? Does the coolant smell of fumes?
That should get you started!
-Pos